v0.4.0 Wave 20: custom layouts + rehearse timings (final v0.4.0 wave)

CHANGELOG.md

@@ -26,6 +26,20 @@ This section tracks work toward v0.2.0 (editor completeness). See
 
 ## [v0.4.0 — in progress]
 
+### Added — Wave 20 (custom layouts + rehearse timings)
+
+- **Layout picker**: a dropdown in the slide context menu showing the
+  current template's available layouts. Selecting one sets the slide's
+  layout and re-renders with placeholder guides.
+- **Rehearse timings**: a "Rehearse" button in the presenter records
+  per-slide durations. When done, timings are committed to the deck. A
+  "Use timings" toggle enables auto-advance — the presenter advances
+  automatically after each slide's rehearsed duration, with a countdown
+  indicator.
+- `Slide.rehearsed_duration_ms: Option<u32>` (additive). New
+  `SetSlideRehearsedDuration` command (reversible).
+- `docs/sprint-records/wave-20.md` documenting the wave scope.
+
 ### Added — Wave 19 (animation enhancements)
 
 - **Trigger model**: build steps now fire on click, with the previous step,

apps/desktop/src-tauri/src/commands.rs

@@ -428,6 +428,10 @@ pub struct SlideSnapshot {
     /// build-ins instantly. `None` defers to the system preference.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub reduce_motion: Option<bool>,
+    /// Per-slide rehearsed duration in milliseconds, for auto-advance. `None`
+    /// means no timing has been recorded yet.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub rehearsed_duration_ms: Option<u32>,
 }
 
 /// A named placeholder frame, mirroring [`slides_core::PlaceholderDef`].
@@ -1403,6 +1407,27 @@ pub fn set_slide_layout(
     Ok(snapshot)
 }
 
+/// Sets or clears a slide's rehearsed duration (for auto-advance) and returns
+/// the updated deck snapshot. Pass `None` (or omit `duration_ms`) to clear the
+/// timing. The change is applied via the verified
+/// [`slides_core::SetSlideRehearsedDuration`] command so it is undoable.
+#[tauri::command]
+pub fn set_slide_rehearsed_duration(
+    slide_id: String,
+    duration_ms: Option<u32>,
+    app: AppHandle,
+    state: State<'_, AppState>,
+) -> Result<DeckSnapshot, String> {
+    let mut guard = state.session.lock().map_err(|e| e.to_string())?;
+    let session = guard.as_mut().ok_or("no deck is open")?;
+    let command = Box::new(slides_core::SetSlideRehearsedDuration::new(slide_id, duration_ms));
+    session.execute(command).map_err(|e| e.to_string())?;
+    let snapshot = state.snapshot(session.deck());
+    drop(guard);
+    schedule_recovery(&app, &state);
+    Ok(snapshot)
+}
+
 /// Opens a PPTX file from the given path and returns its deck snapshot.
 #[tauri::command]
 pub fn open_deck(path: String, state: State<'_, AppState>) -> Result<DeckSnapshot, String> {
@@ -3255,6 +3280,7 @@ fn slide_to_dto(slide: &slides_core::Slide) -> SlideSnapshot {
             .map(|paragraphs| paragraphs.iter().map(paragraph_to_dto).collect()),
         layout_ref: slide.layout_ref.clone(),
         reduce_motion: slide.reduce_motion,
+        rehearsed_duration_ms: slide.rehearsed_duration_ms,
     }
 }
 

apps/desktop/src-tauri/src/main.rs

@@ -58,6 +58,7 @@ fn main() {
             commands::set_presenter_settings,
             commands::set_template,
             commands::set_slide_layout,
+            commands::set_slide_rehearsed_duration,
             commands::list_templates,
             commands::render_slide_svg,
             commands::export_svg,

apps/desktop/src/App.svelte

@@ -25,6 +25,7 @@
     HeadingLevelDto,
     ParagraphDto,
     ParagraphStyleDto,
+    PlaceholderDefDto,
     RecoverySnapshot,
     RunDto,
     SlideSectionDto,
@@ -141,6 +142,21 @@
   /** Name of the layout the active slide uses, or '' when none. */
   const activeLayoutRef = $derived<string>(activeSlide?.layoutRef ?? '')
 
+  /** Effective placeholder frames for the active slide's layout: the deck
+   *  master's placeholders overridden by the selected layout's overrides
+   *  (matched by name). Empty when no layout is selected, so no guides render. */
+  const activeLayoutPlaceholders = $derived.by<PlaceholderDefDto[]>(() => {
+    const layoutName = activeSlide?.layoutRef
+    if (!layoutName) return []
+    const masterPlaceholders = deck?.master.placeholders ?? []
+    const layout = (deck?.layouts ?? []).find((l) => l.name === layoutName)
+    if (!layout) return masterPlaceholders
+    const byName = new Map<string, PlaceholderDefDto>()
+    for (const p of masterPlaceholders) byName.set(p.name, p)
+    for (const p of layout.placeholders) byName.set(p.name, p)
+    return Array.from(byName.values())
+  })
+
   /** Preset aspect-ratio slide sizes, in EMU, matching the Rust constructors. */
   const ASPECT_PRESETS: Record<'16:9' | '4:3' | '16:10', SlideSizeDto> = {
     '16:9': { widthEmu: 12_192_000, heightEmu: 6_858_000 },
@@ -1311,6 +1327,7 @@
             slideSize={slideSize}
             highContrast={highContrast}
             selectedShapeIndex={a11ySelectedShapeIndex}
+            placeholderGuides={activeLayoutPlaceholders}
             onEditTextBox={handleTextEdit}
             onSetCellText={handleSetCellText}
             onCellFocus={handleCellFocus}